Field of the Invention
The present invention relates to a power device. Priority is claimed on Japanese Patent Application No. 2013-120150, filed Jun. 6, 2013, the content of which is incorporated herein by reference.
Description of Related Art
A DC-DC converter which includes two step-up converters connected in parallel has been known. An inductor included in the DC-DC converter is a magnetic-field cancellation type transformer (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2005-224058 and Japanese Unexamined Patent Application, First Publication No. 2006-149054).
A power converter circuit which includes more than three step-up converters connected in parallel has been known. The power converter circuit reduces a ripple current (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2009-170620).
According to the DC-DC converter in the related art described above, when a step-up ratio (a transformer ratio), which is a ratio of an input voltage and an output voltage, is increased to equal to or more than two, the ripple current passed through the inductor is increased. Therefore, it is necessary to enlarge a device, and thereby the loss of circuit is increased.
Moreover, according to the power converter circuit in the related art described above, the number of the step-up converter connected in parallel is increased, and thereby the number of elements needed to configure the circuit is increased. Therefore, the circuit is enlarged.
The present invention provides a power device which can suppress increase of the number of elements needed to configure a circuit and reduce a ripple current when a step-up ratio (a transformer ratio) is increased.